Semiconductor dice must be tested during the manufacturing process to insure the reliability and performance characteristics of the integrated circuits on the dice. Accordingly, different testing procedures have been developed by semiconductor manufacturers for testing semiconductor dice. Standard tests for gross functionality are typically performed by probe testing the dice at the wafer level. Probe testing at the wafer level can also be used to rate the speed grades of the dice. Probe testing is typically performed using a probe card and wafer stepper.
Burn-in testing is typically performed after the dice have been singulated from the wafer and individually packaged. During burn-in testing, the packaged dice are subjected to temperature cycling for extended periods of time, while different electrical parameters of the integrated circuits are evaluated. For burn-in testing, a testing apparatus such as a burn-in board and burn-in oven can be used.
It would be advantageous to be able to burn-in test the semiconductor dice at the wafer level prior to singulation and packaging of the dice. Such a wafer level test procedure would be particularly advantageous in the manufacture of unpackaged dice. With unpackaged dice, carriers must be provided to temporarily package the singulated bare dice for testing and certification as known good dice (KGD). By burn-in testing the dice at the wafer level, the expense associated with temporarily packaging the bare dice for burn-in would be eliminated.